target/sparc: Use memcpy() and remove memcpy32()

target/sparc: Use memcpy() and remove memcpy32()

Rather than manually copying each register, use
the libc memcpy(), which is well optimized nowadays.

Suggested-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20241205205418.67613-1-philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>